Coastal & Marine Geology InfoBank
Our Mapping Systems
The USGS and Science Education
USGS Fact Sheets
ground penetrating radar
Comment: 20:12 - 20:52 (00:40)
Source: Annenberg/CPB Resources - Earth Revealed - 14. Intrusive Igneous Rocks
Keywords: lithosphere, magma, density, plutonic, "igneous rock", intrusion, batholith, pluton, "James Sadd"
Our transcription: Watching a lava lamp can give us a good deal of insight into the way a batholith forms.
When rocks melt in the lithosphere of the Earth, the magma begins to rise because it's less dense than the surrounding rock, just as these bouyant blobs rise through the surrounding oil when the base of the lamp is heated.
As the bubbles of magma make their way toward the surface of the Earth, they begin to expand and pack together coalescing and cooling into a huge mass of plutonic igneous rock.
A composite igneous intrusion like this can be immense encompassing tens, or in the case of a batholith, several hundred individual plutons.
Geology School Keywords